Complex sand mold internal exhaust core bar and operation method thereof

Abstract

The invention discloses a complex sand mold internal exhaust core bar and an operation method thereof, and relates to the technical field of casting production, in particular to the complex sand moldinternal exhaust core bar. The core bar comprises a stainless steel hollow steel pipe, and a vertical hole and a horizontal hole are formed at the outer portion of the stainless steel hollow steel pipe. Reinforcing ribs are fixedly connected to the inner wall of the stainless steel hollow steel pipe and do not coincide with the vertical hole and the horizontal hole in position, and an ignition wire is placed in the stainless steel hollow steel pipe. The small-caliber stainless steel hollow steel pipe is selected as a core bar base layer to guarantee the strength of a mud core, the vertical holes and the horizontal hole are drilled at the periphery of the stainless steel hollow steel pipe, exhaust gas in the mud core is led into the stainless steel hollow steel pipe through pressure difference and then led out of a mud core head, and an air channel can be formed by igniting the ignition wire after a sand mold is hardened. The strength of the mud core can be guaranteed, and meanwhile exhaust of the mud core can be guaranteed.

Description

technical field [0001] The invention relates to the technical field of casting production, in particular to an internal exhaust mandrel of a complex sand mold and an operation method thereof. Background technique [0002] When traditional resin sand is used to cast castings with wooden molds, due to the complex structure of the castings, the cavity and air passages contained in the castings cannot be integrally formed when the outer mold is made, and a core is required to form the shape in the middle. Ni cores are dropped manually during boxing, and core bones need to be interspersed to ensure the strength and rigidity of the ni cores. Especially the nibbles of cast iron small castings often have the characteristics of small size, large quantity and complex structure. (such as cylinder head castings) this kind of core must place the core bone at the weak point, but the volume limit leads to no space to bury the ventilation rope after the core bone is embedded. Internal air...

AI Technical Summary

Problems solved by technology

(such as cylinder head castings) this kind of core must place the core bone at the weak point, but the volume limit leads to no space to bury the ventilation rope after the core bone is embedded. Internal air holding eventually produces a large number of pores and shrinkage cavities inside and on the surface of the casting, which leads to the scrapping of the casting

If the core bone is abandoned and the air channel is directly arranged with a ventilation rope, although this method solves the problem of gas generation in the core, because the internal air channel is hollow and there is no core bone support, the molten iron is easy to break the sand mold during pouring, and it is difficult to drill into the gap to form it. The cleaned iron sand will increase the difficulty of cleaning the back channel, and even cause the casting to be scrapped in serious cases. For this reason, we provide a complex sand mold internal exhaust mandrel and its operation method

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